US947777A - Process of making records for phonographs, &c. - Google Patents

Description

W. SANDERSON. PROCESS 0F MAKING BEUOBDS FOB PHONUGBAPHS, thv. nrm'ox'rmn funn :111.114,1900, :Bunn :uns 1a, 190s.

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WILLIAM SANDEBSON, OF NEW YORK, N. Y.

Pnocnss oF MAKING nnconns ron rHoNoenAPHs, ac.

Specification of Letters Patent.

Patented J an. 25, 1910.

Application led July 14, 1906, Serial No. 826,201. Renewed June 18, 1909. Serial No. 502,969.

To all'whom 'it may concern:

Be it known that I, WILLIAM SANDnnsoN, a citizen of the United States, residing in the borough of Brookl n, in the county of Kings, city and State o New York, have invented certain new and useful Improvements in Processes of Making Records for Phonographs, &c., of which the following is a specification.

This invention relates to an improved process of making records for phonographs or the like.

This invention is especially directed to a process of makina records in disk form, a1- though it is capaile of application to other shapes of records.

Disk records for honographs or other sound reproducing devices are now commonly made of a plastic composition (which is impressed with the sound record by a suitable matrix under the action of a hydraulic or other press. Such composition is usually formed in sheets, and during the operation of molding such sheets are placed upon a steam table which renders the composition suiiciently plastic to be worked. The mold,

which contains the matrix, is then lled with a suitable quantity of the composition, the operator ,cutting olf a sufficient number of pleces to form the finished record. The mold 1s then placed under the press and subjected to a pressure of from to 80 tons, during which time the composition receives the impression of the matrix. This Vprocess is a com aratively slow and laborious` one, and resu ts in a record which is expensive and easily broken.

According to the preferred mode of practicing my invention I take a disk of iron or steel, or other hard tenacious non-hy o scopic material, and apply to such dis al layer or coating of plastic material which is suiiciently thic to receive the sound record,

and'while such material is in a plastic state.

press the sound-record upon it by a suitable matrix. It is im ort'ant that the base shall be constructed o a materialwhich is hard and tenacious, so that it is not liable tobe broken, either in transportation or use. It is also important that such base shall not be affected b the moisture in the atmosphere as otherwise it will be liable Vto warp and thus render the record useless. It is also important that such base be limited in weight. Any material which conforms to these requirements may be used but I prefer sheet iron or steel of suiicient thickness to retain its fiat or other proper form under the conditions of use.

The plastic material (by which term I mean any suitable material which is capable of being rendered plastic to receive the impression 4of the sound matrix, and which afterward hardens) may be of any of the compositions usually emplo ed for this purpose. I prefer a mixture o barites 33 parts, terra alba 1 parts, clay 16% parts, flock 3 parts and she lac 31 parts.

In practicing the process in its preferred form, I first cut the sheet iron or steel into disks of suitable proportions, and thoroughly clean same, whereupon Il apply to one side ofthe disk a layer of paper, asbestos or other suitable fibrous material, preferably by pasting or cementing the paper to the platezuslng for this purpose any suitable adheslve, such as an ordinary casein solution. By this means any contraction or expansion of the plate has no substantial eect u n the plastic composition, and the latter 1s enabled to adhere more eifectually than if it were applied directly tol the metal itself. I may then apply the plastic composition to the disk in any suitable way as by heating the composition and applying it in its plastic form, but I prefer to coat the disk by two separate operations,

by means of which I am enabled to more quickly and conveniently obtain the requisite thickness of coating. To this end l prepare a solution containing a suitable quantit of plastic composition, dissolved in a sultable medium which is adapted todry 'uickly, such as alcohol. I preferably use or thls 100 parts of plastic composition and 62 parts of alcohol, the shellac of the composltion being irst dissolved in the alcohol andv the whole being intimately mixed, preferably by being ground together, This s0- lution is applied to the paper, and i's allowed to dry thereon, this being quickly accomplished by the evaporization of the alcohol. The disks are then taken to the molding room and a further quantity of plastic cornpositionl in a dry', powdered or granulated state is a plied t ereto,preferably by sprinkling it thereon by a sieve or other suitable device.` The disks are then placed upon a steam table and the first coating and the powdered composition are softened so that they become substantially homogeneous, and

with its coated side downward and then places the mold inA the press. During vthe pressing operation the mold is cooled so that the composition hardens after receiving the impression of the sound matrix. After the pressing operation the mold is kept Closed until the record is cool. If desired instead of sprinkling the composition upon the disk before the latter is heated preliminary to the molding operation, it'may be sprinkled thereon after heating, when the first coating is. in a softened state, sufiicient heat being afterward applied to soften the entire composition.

In the drawings, Figure 1 is an eleva-tion of a disk made according to my invention in its preferred form, Fig. 2 is a section thereof prior to the molding operation, the several layers being exaggerated for clearness, and Fig. 3 is a similar View after the molding operation.

In the drawings A is the base, B is the l layer or coating of fibrous material, and C is the layer or coating of plastic material. In Fig. 2 C is the coating of liquid composition and C2 the layer of powdered composition.

The process provided by my invention has several extremely important advantages over those of the prior art. By formin the base of a hard tenacious material o the suitable character, I am enabledvto restrict the quantityof plastic material necessarily used to the minimum. This renderszit feaslble to use the plastic material in the form either of a powder or a liquid solution. Such solution or powder can be easily applied by unskilled labor. I am also enabled to effect an important economy of time during-the molding operation. By my invention it is only necessary for the operator to have a number of disks upon the steam table kept at a suitable de ee of heat, and to place them in the mold as rapidly as the action of the press permits. This may be easily and rapldly done b unskilled` labor, whereas under the-meth s now commonly practiced it takes considerable time to cut the necessary material for each mold from" the sheet and a considerable amount of skill to measure the precise quantity of material which is required for each mold. Each of .the disks prepared according to the present process contains substantially the correct thickness `of plastic material and the operator has nothing further to do than to place them within the molds with the layer of plastic material downward, close the mold and at once place it in the press. Furthermore there 1s no danger of breaking or cracking the record either during the molding operation or in removin the record from the mold. By my inventlon I am also enabled to provide a disk having a sound record on each side, which may be easil accomplished by coating the disk on bot sides with the plastic composition and impressing the sound records thereon by the use of two matrices in a sin le molding o eration. This is a difficult i? not impossibl) operation with prior processes of manufacture.

The new record provided by my invention has numerous advantages over those heretofore made, including a greater degree of durability, and economy of manufacture. I do not herein claim such record, as this forms the subject matter of another ap lic'ation filed by me July 14, 1909, Seria No. 326,202.

Although I have described in detail the preferred process of practicing my invention, Ido not wish to be limited thereto as various changes may be made therein without departing from the spirit of my invention.

An important feature of my invention is the fact that I am enabled to produce a record with an extremely thin coating of composition, and this aids materially lin cheapening the cost of the record.

What I claim is The process of makin records for phonographs or the like whic consists in applymg a layer of fibrous material to a metal base and then forming a layer or coating of plastic composition on said fibrous material and impressing a sound'record on said layer while in its p astic state. In witness whereof, I have hereunto signed my name in the .presence of two subscribing witnesses.

` WILLIAM SANDERSON.

Witnesses:

EUGENE V. MYERS, THEononn T. SNELL.

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